During the Republican National Convention, hundreds of cameras will be eyeing city streets as officials monitor people's movements from a handheld computer the size of a palm pilot.

For the convention, the Federal Protective Service, part of the Department of Homeland Security, has brought to New York 200 patrol officers from around the country, many of them equipped with little surveillance cameras in their helmets. As they move their head, the camera is recording whatever they see and sending the image to a control room.

In the control room — situated in an undisclosed location in Manhattan — and in the service's mobile truck, officers monitor what first line agents have in front of them, as well as what other cameras in federal buildings are taping.

But, almost at the same time, every service commander — each one responsible for an area of the city — will be able to see what its patrol officers are watching, and in case of any disturbances, determine where to send the troops.

"This is an added bonus," said Ronald Libby, regional director for the service. "I want to know what he [a patrol officer] sees to make a decision. ... This takes the guess work out of it."

The signal from the cameras goes directly into the mobile and control units via satellite, and from there, it is fed into the Internet in encrypted form, Libby explained. The handheld devices get the image from the Internet through a wireless connection.

The service is in charge of the security of all federal buildings in the country. During the convention, the agency will not only be securing federal facilities like 26 Federal Plaza and 1 Penn Plaza - near Madison Square Garden - but also patrolling around the city.

The high-tech system, so far only used by the service, was purchased after the Sept. 11 attacks and used for the first time during the Democratic National Convention in Boston last month.

During the GOP gathering, the service will also be supporting other law enforcement agencies and forwarding its images to the police, if necessary, officials said.